Fluid twisting apparatus



Oct. 31, 1961 G. R. LONG FLUID TWISTING APPARATUS Filed May 4, 1959 LIILII ll llllllll INVENTOR GEORGE ROBINSON LONG B WM 11 ATTORNEY rates This invention relates to a process and apparatus for twisting, bulking, or crimping yarns continuously.

It has long been known that a yarn can be crimped by twisting, setting the yarn in the twisted configuration, and then back-twisting the yarn. In a batch process true twist is inserted into the yarn, the yarn is packaged, heat-set, and then back-twisted to give the yarn its crimp and bulk. When such a process is carried out continuously, a temporary twist is imparted to the threadline by a false-twister while simultaneously exposing the yarn to yarn-setting means, e.g., heat, steam, solvent, etc. The temporary twist is removed immediately after leaving the twister, and the yarn is taken up on a suitable package. Such a process is disclosed in copending US. application Serial No. 598,135 filed July 16, 1956, by Breen and Sussman.

Nylon filaments were the first thermoplastic textile materials capable of being heat-set and having adequate recovery from deformation so that bulky and stretch-type Helanca yarns could be prepared. The initial process developed to make such yarns was a batch-type operation in which a continuous yarn was highly twisted, a package of the twisted yarn was then heated under suitable conditions, and then the package was back-twisted to give a yarn that, on relaxation, coiled, curled, or crimped sufficiently to provide great bulk. In addition to the increased bulk, the yarn bundle had the elastic properties of a conventional spring without the helical regularity thereof.

The most time-consuming step in producing so-called Helanca or stretch-yams is twisting. Mechanical twisters with rotating mechanical parts have severely limited rotative speed because of friction and the effect of centrifugal force on the rotating parts. The highest attainable speeds are of the order of 150,000 r.p.m. and this is for a false-twister which is more than nine times as fast as a standard commercial down-twister. Relative efliciency of specially designed false-twisting apparatus and continuous twisting process versus a conventional twister batch process is described in Fibres (Natural and Synthetic), vol. 16, August 1955, p. 276. As described therein, a 60-denier nylon yarn which is twisted 65 turns per inch, heat-set, and then back-twisted via the conventiond twister route (12,000 rpm.) can be handled at the rate of 0.4 pound/spindle/week of 168 hours. A false-twister (32,000 rpm.) can produce this same stretch-yarn at the rate of 1.8 pounds/spindle/week (168 hours) or about 4.5 times faster than the batch operation. One reason why these older processes and false-twisting apparatus have not enjoyed extensive commercial success is their relatively slow speeds, low output and efliciencies, lack of product uniformity, and high maintenance costs which rendered the product very expensive.

One object of this invention is to provide an efficient high speed yarn-twisting device. Another object of this invention is to provide a yarn-twisting device capable of twisting yarn at a rate of over one million turns per minute. Another object of this invention is to provide a process and apparatus for twisting yarns at higher speeds than has heretofore been utilized.

Another object of this invention is to provide a process atent for continuously and simultaneously twisting, plasticizing, deplasticizing, and back-twisting yarn at substantially greater yarn speeds, lower yarn tension, and highter twisting rates than has heretofore been possible.

A further object of this invention is to provide a yamtwisting apparatus and process whereby freshly drawn yarn may be directly (prior to packaging) crimped by continuously and simultaneously twisting, plasticizing, deplasticizing, and back-twisting the yarn. Another object of this invention is to provide a yarn-twisting apparatus and process whereby two ends of freshly drawn yarn (prior to packaging) may be directly crimped by continuously and simultaneously twisting one end in an S direction and the other in a 2 direction, plasticizing, deplasticizing, and back-twisting each yarn end followed by plying the two ends together on the takeup package.

It is a further object of this invention to provide a yarn-twisting apparatus which may be strung-up on-therun.

Another object of this invention is to provide a fluidtwisting apparatus capable of twisting each of a plurality of threadlines in a predetermined direction and beginning or stopping the twisting of all of the threadlines simultaneously.

According to this invention a high speed twisting motion is imparted to a filament, yarn, or other strand by torque applied to the strand by means of a high velocity stream of fluid, preferably air. For a uniform product, tension on the strand, upstream of the fluid stream applying said torque, must be great enough to prevent twist doubling and less than about 60 grams, and is preferably between about 3 and about 15 grams.

In its simplest embodiment, the apparatus of this invention comprises a fluid twister having a tubular yarn passageway which is a smooth curved concave surface associated with one or more fluid conduits positioned to direct a stream of fluid circumferentially about the inner periphery of the concave surface, a string-up slot for introducing an endless yarn into the yarn passageway transversely through the wall thereof, and releasable closure means for separating the yarn passageway from the stringup slot by a partition.

The yarn passageway may be integral with the fluid conduits, or the latter may be spaced apart from the yarn passageway but in position to direct fluid substantially tangentially to the inner periphery of the curved concave surface at some point. The axis of fluid flow (entering the yarn passageway) must not intersect the axis of the yarn passageway, but it may lie in a plane substantially perpendicular to the longitudinal axis of the concave surface, or in a plane inclined up to about degrees or more from this perpendicular in order to exert forward movement or braking action upon the yarn in addition to twisting motion. There may be a plurality of conduits directing fluid flow about the periphery of the concave surface, and these conduits may be spaced longitudinally or circumferentially or both about the yarn passageway. Naturally, in order to obtain the highest degree of torque on the yarn, all of the fluid conduits, where there is a plurality, should be directed in substantially the same tangential direction. It is not necessary, however, that the longitudinal axes of all the fluid conduits lie in the same or parallel planes with respect to the axis of the yarn passageway. One or more or a plurality of fluid conduits may have axes perpendicular to the axis of the yarn passageway while one or more others may have axes inclined to impart forwarding and twisting motion to the yarn while a lesser number of fluid conduits may have axes inclined backward toward the axis to partially inhibit the passage of the yarn therethrough. In the case where there are a plurality of fluid conduits supplying fluid to the yarn passageway, it may be desirable to provide one or more exit ports along the yarn passageway, and these may be positioned at any convenient points.

The process and preferred embodiments of the apparatus of this invention can be more readily understood by referring to the attached drawings, FIGURES I-V.

FIGURE I illustrates a string-up assembly using the dual fluid twister shown in FIGURE IV.

FIGURE II shows in cross section the slotted hot plate of FIGURE I with threadlines 1 positioned in the slots.

FIGURES III-V illustrate preferred embodiments of the twisters of this invention.

FIGURE III illustrates a fluid twister particularly useful in this invention in being particularly adapted for ease of string-up. In this twister, yarn passageway 51, substantially cylindrical in form throughout its length, is intercepted by fluid inlet 52, the latter being positioned so that the longitudinal axis of the fluid inlet does not intersect the longitudinal axis of the yarn passageway. Yarn passageway 51 has its walls formed partly by a recess 45 in the body of twister 50 and partly by recess 46 in a close fitting movable cylinder 49 positioned within the twister, the axis of the cylinder being parallel to the axis of the yarn passageway. By rotating cylinder 49 as with handle 48, recess 46 can be brought into communication with V groove 47 for string-up purposes. By passing a yarn through the V groove and into recess 46, then rotating cylinder 49 until recesses 45 and 46 are aligned, the twister is made ready for operation. It is not necessary that the walls of yarn passageway 51 be evenly distributed between cylinder 49 and body 50. It is only necessary that the recess 46 be capable of receiving a yarn through V groove 47 and be large enough so that cylinder 49 can rotate within body 50 without snagging or abrading the yarn unduly.

It is not essential, of course, that the yarn passageway 51 have its walls formed by recessed sections of both body 50 and cylinder 49 because yarn passageway 51 may be wholly confined in either body 50 or cylinder 49 so long as suitable access to the yarn passageway is provided to permit string-up on-therun.

The twister of FIGURE IV is similar to that of FIG- URE III but is capable of handling two strands simultaneously while providing for constant fluid pressure on each of the strands and also adapted so that treatment can be started and stopped precisely at the same instant. The simultaneous functioning of the two fluid twisters is achieved by actuating handles 48 and 48' simultaneously by movement of yoke 44. A downward movement of the yoke brings both recesses 46 and 46 into communication with V grooves 47 and 47' for introduction of the respective yarns to be treated. An upward movement of the yoke rotates cylinders 49 and 4% until yarn passageways 51 and 51 are simultaneously formed. Fluid pressure entering yarn passageway 51 from manifold 61 through fluid inlets 52 and 52 instantly acts upon each of the threadlines simultaneously. Processing of both threadlines is simultaneously terminated by lowering yoke 44.

FIGURE V is a side view of the dual twister of FIG- URE IV.

The twisting apparatus of this invention is particularly useful in carrying out the process of twisting yarn as set forth in the copending US. application Serial No. 810,- 671 of Alvin L. Breen and Martin V. Sussman filed on the same date as this application as well as the processes set forth in copending applications Serial No. 598,135 filed July 16, 1956, and Serial No. 754,912 filed August 12, 1958, both by Breen and Sussman, and the disclosure in these applications is applicable to the practice of the present invention. Therefore, the disclosure of all these applications is incorporated by reference into this specification and made a part thereof.

FIGURE I shows a string-up assembly in which two threads are run simultaneously on each position and drawn to the large diameter portion of stepped roll 162 and about separator roll 164; The yarns then pass up to the nylon gears which act as twist snubbers and thence they are separated by the guide pins 169 and are heated in separated individual grooves in hot plate 168. One yarn passes through fluid twister 167 which operates to impart Z twist, and the other yarn passes through fluid twister 166 which imparts S twist. Both yarns then pass around the small diameter portion of stepped roll 162 followed by winding up together on a pirn takeup or the like. The pirn takeup is advantageous in allowing plying of the S and Z twist crimped yarns to give a balanced stretch-yarn without twist liveliness.

It is essential for the successful processing of yarn according to the string-up of FIGURE I that twisting of both yarns begins simultaneously. For this purpose the double-throw dual twister of FIGURE IV is utilized.

Examples 93, 95, 96, and 97 of copending applica tion Serial No. 810,671 filed by Breen and Sussman on even date show the production of products using the dual twister of FIGURE IV in the assembly of FIG- URE I.

The claimed invention:

1. A fluid twister comprising a tubular yarn passageway, an inlet for admitting fluid into the yarn passageway and positioned to direct said fluid circumferentially about the inner periphery of the yarn passageway, a string-up slot for introducing an endless yarn transversely into the yarn passageway and releasable closure means for partioning the yarn passageway from the string-up slot.

2. A fluid twister comprising a plurality of yarn passageways, each having at least one inlet for fluid positioned to direct said fluid circumferentially about the inner periphery of that yarn passageway, at least one string-up slot for introducing an endless yarn into each yarn passageway through the wall thereof, releasable closure means for partitioning each yarn passageway from the string-up slot, and means for simultaneously actuating the flow of fluid into each of the yarn passageways.

3. A fluid twister comprising a body perforated by a cylindrical tunnel, a cylinder having the same diameter as the tunnel rotatably mounted therein, a tubular yarn passageway longitudinally disposed with respect to the axis of the cylinder and partially formed by a concavity in the cylinder wall with the remainder formed by a concavity in the wall of the tunnel, fluid inlet means communicating between the exterior of the body through the tunnel wall and cylinder to the yarn passageway and positioned to direct said fluid circumferentially about the inner periphery of the yarn passageway, 21 string-up slot for introducing endless yarn transversely into the concavity in the cylinder wall and comprising a channel longitudinally disposed with respect to the tunnel axis and communicating with the tunnel throughout its length but at an area on the wall of the tunnel spaced from the fluid inlet interception therewith, and means for rotating the cylinder from a position where the concavity in its wall is in register with the concavity in the tunnel wall (thereby forming the tubular yarn passageway) to a position where the concavity in its wall is in register with the string-up slot.

4. A multiple fluid twister comprising a body containing a plurality of the fluid twisters of claim 3, means for supplying the fluid inlets of each of these twisters with fluid from a common source and means for simultaneously rotating each of the cylinders of the twisters from a position where the concavity in its wall registers with References Cited in the file of this patent UNITED STATES PATENTS Cooper Feb. 14, 1911 6 Claus Nov. 30, 1937 Foster et a1. July 18, 1950 Boillal et a1 Dec. 9, 1958 Stucki Jan. 20, 1959 Breen Jan. 20, 1959 Willens June 16, 1959 Bauer May 31, 1960 

